A New simple diagnosis method for intense ion beam utilizing back scattered particles with CR-39 detectors

Kanasaki, Masato; Yamauchi, Tomoya*; Fukuda, Yuji; Sakaki, Hironao; Hori, Toshihiko; Tampo, Motonobu; Kondo, Kiminori

A new diagnosis method for high energy ion beam has been developed utilizing backscattered particles. A single 100-m thick CR-39 detector mounted on a 3-mm thick backscattered was irradiated with He ions with an energy of 25 MeV/. Although this energy is too high to create etchable tracks on both surfaces of the CR-39, we found that a number of elliptical pits as well as circular ones were created on the rear surface. The existence region of the elliptical pits well reproduced the initial ion beam pattern. Detailed investigation of growth pattern of each pit size revealed that most of etch pits in the rear surface were created by backscattered He particles. The results indicate that using this method it is possible to identify energy, number, and profile of high energy ion beam which is insensitive to CR-39.